Thermoplastic resin composition including wood and fibrous materials

ABSTRACT

A thermoplastic resin composition is disclosed for use as structural, packing and other industrial materials. The composition essentially comprises thermoplastic resins, wood materials, synthetic, inorganic or regenerated fibrous materials and preferably synthetic or natural rubbery materials.

United vStates Patent Shinomura June 10, 1975 THERMOPLASTIC RESINCOMPOSITION [56] References Cited INCLUDING WOOD AND FIBROUS UNITEDSTATES PATENTS MATERIALS 2,635,976 4/1953 Meiler et a1. 260/l7.4 75Inventor: T i i shinomura, K ki 2,663,693 12/1953 HESS eta]. 260/4 Japan3,474,048 10/1969 Chappe Lear et a1. 260/25 3,709,845 l/l973 Boustany eta]. 260/17.4 [73] Assignee: Nippon Oil Co., Ltd., Tokyo, Japan PrimaryExaminer-Melvin Goldstein [22] Flled July 1973 Assistant Examiner-EdwardWoodberry [21] Appl. N0.: 377,711 Attorney, Agent, or Firm-Frank J.Jordan [30] Foreign Application Priority Data [57] ABSTRADC? Jul H 1972la an 47 69222 A thermoplastic resm composition is disclosed for use y pas structural, packing and other industrial materials. [52] U S 0260/174 260/17 4 260/17 4 CL The composition essentially comprisesthermoplastic [51] C08 45/18 resins, wood materials, synthetic,inorganic or regen- Fie'ld 4 BB erated fibrous materials and preferablysynthetic or 260/9, 41 R, 41 A, 41 C, 41 AG natural rubbery materials.

3 Claims, N0 Drawings THERMOPLASTIC RESIN COMPOSITION INCLUDING WOOD ANDFIBROUS MATERIALS BACKGROUND OF THE INVENTION This invention relates tothermoplastic resin compositions suitable for use as structuralmaterials, packing materials and so on, and more particularlyto'thermoplastic resin compositions comprising predetermined amounts ofstarting resins, dry wood materials, synthetic or inorganic fibrousmaterials and preferably rubbery materials.

There have been hitherto proposed several wood-like materials consistingmainly of synthetic high polymers or the so-called synthetic wood ascontrasted to naturally-occuring wood. Typical examples arefoamedsynthetic resins, synthetic resins added with minute hollow elements,hydrous polyesters, synthetic resins filled with pigments and the like.Some of them have found commercial use to some extent, but most of themare not entirely satisfactory because of their low mechanical strength,elasticity and machinability essential to wood materials. Anotherdisadvantage of these prior-art materials is that they are difficult tobe discarded or regenerated and further that their manufacturing costsare prohibitive.

On the other hand natural wood resources have been increasinglydiminishing, and labour costs for logging and machining the wood andtimber have been raised tremendously. The treating of waste materials ofwood such as bark-dust, saw-dust and wastes from papermills produces alarge social problem.

SUMMARY OF THE INVENTION Whereas, it is an object of the presentinvention to provide at relatively low cost improved thermoplastic resincompositions of this character which have ideal proportions of many ofthe desirable properties including mechanical strength, elasticity,nailability, sawability and the like.

Other objects and features of the invention will be apparent from thefollowing description taken in connection with certain preferredembodiments.

Briefly stated, the compositions of the present invention comprise 100parts by weight of starting thermoplastic resins, l 500 parts preferably50 200 parts by dry weight of waste wood materials such as sawdust,bark-dust, waste materials produced during the paper making and the likeand 2 200 parts preferably 30 parts by weight of synthetic, inorganic orregenerated fibrous materials. According to another aspect of theinvention, these may be further added up to 30 parts by weight ofnatural or synthetic rubbers.

The term thermoplastic resins or the first component as used hereinincludes polyethylene, polypropylene, polystyrene, polyvinyl chloride,acrylonitrile-styrenebutadiene resin and their copolymers or blends.

The term saw-dust and bark-dust or the second component includes suchwood dust of below five mesh available from logging processes. Thepaper-mill wastes herein referred to collectively embrace waste knots,settler wastes, fine pulp, drainage, cellulosic powder and the like. I

The term fibrous materials or the third component includes polyesterfiber, polyamide fiber, polyacrylic fiber, glass fiber, asbestos,silica-alumina fiber, rayon and the like.

It has been found that the second component when added in amounts ofless than 10 parts by weight will reduce the qualities of sawing,nailing, elasticity and heat insulation. However, amounts of thiscomponent in excess of 500 parts by weight are infeasible.

The third composition when added in amounts of less than 2 parts byweight will result in poor mechanical strength and elasticity. Butamounts in excess of parts are impracticable.

It has been further found that the wood materials specified herein abovewill not only serve to reduce the production cost but also improve thesawability, nailability, heat insulation and combustibility. However,simple addition of these wood materials alone to the starting resinswill not give appreciable rise to mechanical strength, elasticity, creepresistance or nail pulling resistance. One known method for improvingthese physical properties is to use the graft polymerization of certainmonomers with wood powder. According to the present invention,satisfactory results are obtained by adding synthetic, inorganic orregenerated fibrous materials of the type described.

In accordance with thepresent invention, it has also been found thatsynthetic rubber such as styrenebutadiene rubber, butadiene rubber,butyl rubber, acrylonitrile-butadiene rubber (NBR) andethylene-propylene rubber, or natural rubber may be advantageously usedas a thickener in amounts of 30 parts or less, preferably 1 20 parts byweight. If necessary, various other additives may be used.

DESCRIPTION OE THE PREFERRED EMBODIMENTS The following examples areprovided to further illustrate the present inventionbut these are not tobe regarded as limiting.

INVENTIVE EXAMPLES I -IV 100 parts by weight high density polyethylene(HDPE) having a melt index of 5.0 and a density of 0.96 was treated at aroll temperature of C in accordance with the recipe given in Table I.The admixture was fabricated by pressing at C and 200 kg/cm into asheet. Test data of these products are given in Table I whereinComparative Examples are provided by way of contrast. The products weretested to show high mechanical strength and elasticity, moderately lowelongation, excellent sawability and nailability and combustibilitycomparable to natural wood. The nylon staples used herein were made ofnylon 6 of 3 denier having a cut length of 10 mm. The polyester staplesused herein were made of polyethylene terephthalate of 2 denier having acut length of 7 mm. In Inventive Example I a predetermined amount ofstyrene-butadiene rubber (SBR) was added with good results. Similarresults were also obtained by the addition of natural rubber.

INVENTIVE EXAMPLE V 100 parts by weight high density polyethylene(HDPE)-having a melt index of 5.0 and a density of 0.96 was admixed asin Table l with a dry blend of cellulosic powder (passable through a 10mesh filter) and glass fiber (6 mm chopped strands treated with acoupling agent). The admixture was applied to an extruder thereby tofabricate a sheet.

INVENTIVE EXAMPLE v1 100 parts by weight polypropylene (PP) having aINVENTIVE EXAMPLE VIII melt index of 5.0 was used in accordance with therec- 5 roll temperature of 190 200C. The admixture was ipe of Table IIand treated at a roll temperature of fabricated by pressing at 200C and200 kg/cm into a 180C. The admixture was fabricated by pressing atsheet. Test data of this product are given in Table II 200C and 200kg/cm into a sheet. Test data of this wherein Comparative Example VI isprovided by way product are given in Table 11 wherein Comparative Exofcontrast. am 1e IV is rovided b wa of contrast.

p p y y INVENTIVE EXAMPLE IX parts by weight high density polyethylenehaving INVENT AM VII a melt index of 5.0 and density of 0.96 was admixedwith wood powder and rayon staples in accordance 100 parts by weightpolystyrene (PST) was treated as 15 with the recipe given in Table II ata roll temperature in Table II at a roll temperature of C. The of 160 C.The rayon staples used herein were of admixture was fabricated bypressing at C and 200 3 denier having a cut length of 10 mm. Theadmixture kg/cm into a sheet. Test data of this product are given wasfabricated by pressing at 180C and 200 kg/cm in Table 11 whereinComparative Example V is prointo a sheet. Test data of this product aregiven in Table vided by way of contrast. 20 II.

Table I Bending Bending Breaking M1 *3 Breaking Recipe Modulus *1Strength *1 Strength *2 Elongation *2 (kg/cm) (kgl m g/ g/ ComparativeHDPE 100 1.16 X 10 174 212 76 134 2 Example I (yield point) ComparativeHDPE 100, wood powder 100 2.19 X 10 148 100 94 1.2

Example II Comparative HDPE 100, SBR 20, 1.95 X 10 124 96 96 1.0

Example 111 wood powder 300 Inventive HDPE I00, SBR 20, 3.43 X 10 314248 240 1.1

Example 1 wood powder 400, nylon staples 1O Inventive HDPE 100, woodpowder 100, 3.35 X 10 384 245 232 1.3

Example 11 nylon staples 20 Inventive HDPE 100, waste knots 20, 3.74 X10" 443 255 242 1.2

Example 111 polyester staples 7O Inventive HDPE 100, settler wastes 200,2.93 X 10 224 192 186 1.1

Example IV silica-alumina fiber 5 Inventive HDPE 100, cellulosic powder3.15 X 10 304 235 1.4

Example V 50, glass fiber 20 Note:

*1 These values were measured according to ASTMD-790-66.

"2 These values were measured with an example sheet of 50 mm in length.10 mm in width and 2 mm in thickness at a deformation velocity of 5mm/min. *3 These data show stress corresponding to 17: of strain inmeasuring item 2.

Table II Bending Bending Breaking M Breaking Recipe Modulus StrengthStrength Elongation g/ g/cm") gl g/ Comparative PP 100, wood powder 1001.85 X 10 172 114 102 1.3

Example IV Comparative PST 100, wood powder 100 2.75 X 10' 244 122 1221.0

Example V Comparative PVC 100, stearic acid 1, 2.92 X 10 314 135 112 1.2

Example VI butyl stearate 1,

wood powder 100, *4 DBTM 3.5, *5 DBTL 0.1 Inventive PP 100, wood powder100, 3.25 X 10 335 235 210 1.4

Example VI polyester staples 15 Inventive PST 100. wood powder 100 4.81X 10" 484 259 234 1.2

Example Vll n lon 20 Inventive P C 100, stearic acid 1, 5.26 X 10 643281 212 1.6

Example V111 butyl stearate 1,

wood powder 100, *4 DBTM 3.5, *5 DBTL 0.1, polyester staples 10Inventive HDPE I00, wood powder 100 3.05 X 10 328 212 197 v 1.1

Example IX rayon staples 20 Note:

4 DBTM is a stabilizer of tin maleate. *5 DBTL is a stabilizer of tinlaurate.

ca-alumina fiber and rayon.

2. The thermoplastic resin composition as defined in claim 1 whichfurther includes up to 30 parts by weight of natural rubber.

3. The thermoplastic resin composition as defined in claim 1 whichfurther includes up to 30 parts by weight of synthetic rubber selectedfrom the group consisting of styrene-butadiene rubber, butadiene rubber,butyl rubber, acrylonitrile-butadiene rubber (NBR) andethylene-propylene rubber.

1. A THERMOPLASTIC RESIN COMPOSITION COMPRISING 100 PARTS BY WEIGHT OFONE OR MORE THERMOPLASTIC RESINS SELECTED FROM THE GROUP CONSISTING OFPOLYETHYLENE, POLYPROPYLENE, POLYSTYRENE, POLYVINYL CHLORIDE ANDACRYLONITRILE-STYRENEBUTADIENE RESIN; 10 - 500 PARTS BY DRY WEIGHT OFONE OR MORE WOOD MATERIALS SELECTED FROM THE GROUP CONSISTING OFSAW-DUST, BARK-DUST AND PAPER-MILL WASTES; AND 2 - 100 PARTS BY WEIGHTOF FIBROUS MATERIALS SELECTED FROM THE GROUP CONSISTING OF POLYESTERFIBER, POLYAMIDE FIBER, POLYACRYLIC FIBER, GLASS FIBER, SILICA-ALUMINAFIBER AND RAYON.
 2. The thermoplastic resin composition as defined inclaim 1 which further includes up to 30 parts by weight of naturalrubber.
 3. The thermoplastic resin composition as defined in claim 1which further includes up to 30 parts by weight of synthetic rubberselected from the group consisting of styrene-butadiene rubber,butadiene rubber, butyl rubber, acrylonitrile-butadiene rubber (NBR) andethylene-propylene rubber.